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Discussion Starter #1
OK, I have filled my new 2011 TDI Sport Wagon with diesel three times now when the gauge was about in the middle of the red range. Twice it has taken 14.5 gallons upon filling. When I looked in the manual for fuel tank capacity it said 14.5 gallons! Am I cutting it too close, or is there some reserve fuel in addition to the stated capacity?

BTW - I have wanted a VW TDI for years and finally got one. Lovin it so far!
 

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Welcome to the forum. welcometomyturbodies

Well the US spec is 14.5 US gallons which is 54.88 litres the Euro spec is 55 Ltr which is 12.1 UK gallons.

I find once the fuel warning comes on is shows shows 50 miles left which you thing is quite long but it soon drops off as the fuel gauge isn't proportional. Now I had mine show 25 miles so I went home to pickup the petrol can for the lawn mover. When I started up again it shows 5 miles so how can you loose 20 miles sitting in the drive? I drove 300 yards up the road and it showed 0 miles I travelled 4 miles to fill it up again, it only took 54 litres so there was supposidly 1 litre left.
 

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I agree that the 2011 JSW fuel tank is larger than advertised. At 1/4 on the fuel gauge it takes 12-gallons before the fuel pump clicks and stops the transfer, at 1/8 on the fuel gauge it takes 14-gallons. Doing the math and assuming the tank curve is linear, the fuel tank capacity is 16-gallons.

I wonder if the same relationship exists at the 3/4 mark and 1/2 mark on the fuel gauge.

Given the potential for catastrophic damage to the HPFP, I would not push too deep into the red shaded section of the fuel gauge.

How many miles do you post on the dash before you see the fuel gauge drop off of the full mark? I am seeing between 50 and 70-miles before the fuel gauge starts to drop below the full line.

***MINOR TOPIC SHIFT***
Part of that extra capacity may be tank venting. My 2003 Jetta TDI had a small plastic post at the top of the filler spout. At the time the TDI goal was to get a 700-mile tank, which was achievable but not without pushing some limits. The key trick to the 700-mile tank was to 'vent' the fuel tank after the nozzle clicked and you could get an extra gallon or so into the tank. When the fuel nozzle clicked you would pull the nozzle out of the filler spout and then press the vent post and you could hear the tank vent itself, when the audible sound of air passing thru the filler spout stopped, you would reinsert the fuel nozzle and keep filling.

On my 2011 JSW I do not see the manual venting post in the filler neck, which makes we wonder how the current tank design vents during fueling and if 'some' of the additional fuel capacity is in the fill spout.
 

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I agree that the 2011 JSW fuel tank is larger than advertised.
It isn't that its larger than advertised its the US gallon is smaller than the UK gallon.

How many miles do you post on the dash before you see the fuel gauge drop off of the full mark? I am seeing between 50 and 70-miles before the fuel gauge starts to drop below the full line.
I can drive 80-90 miles before it drops of the full mark, as I said its not proportional.
 

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Discussion Starter #5
I have noticed as much as 100 miles before the gauge moves off full. (Highway)

In reading the manual it says fuel capacity is 14.5 gallons including a 2 gallon reserve. The way I read it that means a 12.5 gallon tank with a 2 gallon reserve for a total of 14.5, but maybe what they mean is a 14.5 gallon tank with a 2 gallon reserve for a total of 16.5 gallons? Either way, I think I will try to fill up a little earlier than I have been.

I used to have a golf back in the 80's and one thing I remember about it was that Empty meant Empty! No driving 20 more miles after the needle hits E!
 

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Well there is no reserves on cars you don't flick a switch. If it says it a 14.5 gallon tank then thats US gallons.

I remember many years ago when we used to have Triumph Heralds over here they used to have a reserve capacity in the fuel tank and you had to get out and open the boot and turn a lever on the fuel tank so it sucked fuel from another compartment.
 

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Wondered about "reserve" many times

I've wondered about the use of "reserve" many times. Why even call it that if you don't know when you're using it. I remember having dual tanks on an old Ford pickup truck. When one was empty, I just switched to the other. That was a reserve tank.
 

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I too have had several 15 US gallon fill ups in my 2010 JSW TDI with a 14.5 gallon tank. I attribute this to several things:
1. There is extra capacity built into the fuel system with venting, amount of fuel in the fuel lines from the tank to the HPFP. The other item to consider is the amount of fuel that can be held in the fuel filler neck (up to 3/4 of a gallon on some vehicles).
2. Fuel level sensor accuracy. While the days of a cork float on a wire are over this is something to consider.
3. Most important, accuracy of the pump at the station dispensing the fuel. If you look at the pump (U.S. only) there should be a sticker confirming that the pump has been checked within the last twelve months for accuracy. In my state this is done by the Dept. of Agriculture Bureau of Standards. You would be amazed at how many fuel stations have not been checked recently. Whose favor do you think their pumps are working in YOURS?

Your Mileage May Vary

cheers
dave parker
 

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Discussion Starter #10
Dave -
I agree with all your points. #3 probably isn't a problem as I haven't filled at the same place twice yet and I hope that would only be an issue in isolated cases.

With my gasoline cars, I have always run them out of gas intentionally (with a spare gas can of course!) once just to see where on the guage Empty really is. For obvious reasons, I can't do that with the TDI. I guess I'll just have to wonder about it until I run accross someone who has acutally run one dry!
 

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I have had at least two 15 US gallon fillups in my 2011 JSW. With a tank getting close to 600 miles. The last time it took 15.2 gallons and as I pulled up to the diesel pump the dash flashed REFUEL NOW!
14.5 gallons ....Hmmmm
 

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fuel gauge

i have a 2011 jetta tdi the fuel gauge goes off full after 130 miles gauge jumps in eighth tank increments is this normal or is there ajustments. been down to empty end with 5 miles left pump kicks off at 14.3 gallons.
 

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tdi-save$
Yes.
There is an adjustment to the level sensor but it is not something that the owner or shade tree mechanic can do.

cheers
dave parker
 
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